Method of preparing soles.



K. ENGEL.

METHOD OF PREPARING SOLES.

ED EB 4 1918 APPLIC 1,281,549., Patented 00t.15, 1918.

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KARL ENGEL, OF ARLINGTON, MASSACHUSETTS, ASSIGNOR TO UNITED SHOE MACHIN- ERY CORPORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

METHOD OF PREPARING SOLES.

Specification of Letters Patent.

Application filed February 4, 1918. Serial No. 215,339.

.of boots and shoes and particularly to improvements in methods of preparing outsoles for incorporation in shoes. The shank portion of the foot, between the support provided by the heel of a shoe and the support provided by the ball of the shoe, requires a definite support in the shoe which the sole alone is not adapted to afford. So called shank stifl'eners have therefore commonly been applied to the bottom of a lastedshoe before the outsole is attached, these stiffeners of wood or metal being usually tacked to the insole. Sometimes a bulky filling, which may or may not include a stiffening element,

is applied to the shank portion of the shoe before the outsole is applied. These expedients, while not without some degree of utility, fail to satisfy fully the requirements of efiicient manufacturing conditions and are, moreover, faulty in principle. The out-- sole and not the insole is the strong element of the shoe shank and if it is not strong and stiff enough efficiency calls for reinforcing the already strong member, rather than bracing up the insole which is not adapted orintended to stiffen the shank, or by inserting a stiffener independent of the outsole. This problem has been dealt with initially by the invention described in my copending application Ser. No. 863,758, filed Sept. 26, 1914. By that invention I have contributed to the art the broad method which consists in assembling a sole and a moldable shank stifi'ener and then simultaneously molding the sole and shank stiffener to the desired shape prior to their being assembled in the shoe.

The specific problem under consideration in the illustrated embodiment of that invention was the reinforcement of the shank portion of the soles of shoes which it is desirable shall possess a. resilient shank, including childrens shoes. I have in accordance with the same principle herein applied the invention to the production of shoes for heavier wear, including mens and womens footwear. For this type of shoe a rigid or practically rigid support for the shank of the shoe is desirable, and that result is herein obtained by the incorporation with the sole of a shank-shape preserving element by a method which affords maximum advantages in the shoe product with minimum cost of shoe production.

In one of its aspects the present invention is found in that improvement in methods of preparing outsoles for incorporation into shoes which consists in molding a shankshape preserving element, for example of malleable sheet iron, into the shape desired in the shank portion of a shoe, then assembling this molded element with a sole blank, as for example a died out leather sole properly tempered to render it most advantageously moldable, and molding the sole blank into the same longitudinal and transverse curvatures as those previously given to the shank-shape preserving element. By

this procedure I produce a prepared sole consisting of a single multi-ply structure in which exact likeness of shape of the two superposed elements is insured and, because they are molded together into intimate relation, the two elements reinforce each other and a maximum of strength is secured in the product from a minimum of value and bulk in the elements. Advantageously the shapepreserving element is embedded into the tempered, and therefore soft, sole during the molding of the sole upon the said element and also the two elements may well be attached together in molded condition as, for example, by forming prongs or tangs on the metal element and fastening the sole,to said element by said prongs during the sole molding operation. It has been proposed to effect the molding simultaneously and together of a soft metal shank blank and out sole. The present method avoids many practical limitations to the use of that method, which of course can be practised only with metal which is so soft that it can be molded with the sole as a backing, or conversely, it requires the sole to be of such firm stock and so dry andhard as to enable the metal to be molded by pressure applied through the sole leather, else the shaping of the metal piece is incomplete and imperfect. By the Patented Oct. 15, 1918. y

improved method of the present invention the forming of the shape-preserving element is perfected independently of the forming of the relatively softer tempered leather. Identity of shape can thus be imparted both to the metal and the relatively soft leather and limitations as to the quality of metal and of leather employed are eliminated. Also by the present method, it is practical to embed the molded metal into the adequately softened and tempered sole leather, thus condensing and improving the shank preserving qualities of the leather while pro ducing compactness and symmetry of outline in the prepared sole. In the old method the sole was weakened by recessing or gouging it in order to get the metal into desired relation to the sole surface.

In the use of the soft metal required by the old method the requisite rigidity of the stiffened shank of the sole was largely dependent upon having a transverse as well as a longitudinal curvature imparted to the metal strip. Such transverse arching of the shank is permissible --in some styles of womens shoes but is inconsistent with the prevailing shapes of a great many shoes.

The invention will be more fully understood from the following detailed description with the aid of the accompanying drawings, of the way in which I have successfully-practised the same, and the invention will then be definitely pointed out in the claims.

Figure l of the drawings illustrates in plan View and side elevation one form of shank shape-preserving element such as may be used in the practice of the method of the present invention;

Fig. 2 is a longitudinal cross-sectional view showing the shank shape-preserving element in position to be acted upon by the shaping molds;

Fig. 3 illustrates the operation of the shaping molds;

Fig. 4 is a perspective View of the article produced by the practice of the present invention;

Fig. 5'is a longitudinal cross section illustrating the sole and the shank shape-preserving element assembled for the operation of the sole shaping molds;

Fig. 6 is a transverse cross section illustrating the assembled relation of the parts as shown in Fig. 5;

Fig. 7 is a transverse cross section illustrating the operation of the sole shaping molds; and

Fig. 8 is a detail section showing one of the attaching tangs provided for the shank shape-preserving element.

In practising this method I cutout blanks preferably having corner prongs 2 from sheet metal possessing the desired degree of hardness to meet the requirements of the asreao to be used. The blank is then molded to the precise shape that it is desired to have the shank of the shoe possess, both as to longitudinal curvature or inclinations and as to transverse curvature. This is done between dies or molds I and 6 which may be of well-known construction and operated by any usual mechanism. Advantageous blank positioning or holding means will be employed to insure accuracy of relation of the blank to the dies during the shaping operation and I have shown two pilots 5 adapted to cooperate with recesses located in predetermined position in the blanks.

The blank shown in Fig. 1 is transformed by the dies into the shank-shape preserving element 10 shown in Figs. 3 and 7 The prongs are advantageously downturned during this operation by proper construction of the acting portions of the dies. The element 10 now has the shape to fit upon the molding face of the sole molding die 12- upon which it is placed, with the aid as shown of pilots '15, and then the sole blank, which may have been previously died substantially to final edge contour, is assembled with element 10 in proper longitudinal and transverse position between dies or molds 12 and 14. These molds are operated by means well known in the sole molding art, and thefirst step is to bend the sole blank longitudinally and transversely into near parallelism with the opposed face of the element 10, then to press the bent sole upon the prongs 2 and fasten it to the metal element 10 in bent condition. As the pressure continues, there being of course no separate stages in the application of the pressure, the sole-blank, which is preferably well tempered and mulled to render it most responsive to molding action, is molded upon the element 10 and to the exact shape which has been previously given to said element, and advantageously is firmly attached by the prongs 2 which hold it in molded shape while the' sole subsequently dries and until the molded sole isincorporated in the shoe of which it is to become a part. It is practical, and I prefer so to do, to embed the metallic shape retaining element 10 into the softened sole by the degree of pressure to which soles can be subjected in this operation, thereby condensing and improving the shank-serving qualities of the sole and at the same time rendering the surface of element l0 fiush or substantially flush with the adjacent portion of the sole surface. The bulkiness of the shoe in the shank is therefore not increased by the presence of the shape retaining element 10; and the shank portion of the shoe is rendered rigid or substantially rigid by the minimum addition of stiffening material because the sole and the element 10 pressed into a unitary multi-ply structure reinforce each other and the prongs 2 fasten them securely together, and because the portion of the sole under the element 10 is rendered additionally stifl' by being compressed. Numerous other advantages will also be recognized by those conversant with practical shoe manufacturing.

Having explained the nature of this invention and described how it may be practised, I claim as new and desire to secure by Letters Patent of the United States 1. That improvement in methods of preparing outsoles for incorporation into shoes which consists in molding a shank-shape preserving element into the shape, including the longitudinal and transverse curvatures, desired in the shank portion of a shoe; then assembling said molded shape-preserving element with a sole blank and molding the sole blank into the same longitudinal and transverse curvatures as the molded shank element.

2. That improvement in methods of preparing outsoles for incorporation into shoes which consists in molding a shank-shape preserving element into the shape, including the longitudinal and transverse curvatures, desired in the shank portion of a shoe; then assembling said molded shape-preserving element with a sole blank and molding the sole blank to the shape of the shape-preserving element, and securing said molded elements together.

3. That improvement in methods of preparing outsoles for incorporation into shoes which consists in molding a shank-shape preserving element into the shape, including the longitudinal and transverse curvatures, desired in the shank portion of a shoe; then assembling a sole blank on the molded stifiener and. by use of the stiffener as a portion of the sole molding form, molding the sole blank to the shape of the stiffener.

at. That improvement in methods of preparing outsoles for incorporation into shoes which consists in molding a shank-shape preserving element into the shape, includ ing the longitudinal and transverse curvatures, desired in the shank portion of a shoe; then assembling a tempered sole blank on the molded stiffener and, by use of the stitl'ener' as a portion of the sole molding form, em-

bedding the stiffener in the sole blank and molding the sole blank and stifiener into a multi-ply structure in which both elements have the same transverse and longitudinal curvatures and present an approximately uninterrupted surface on the stiflener-containing side of the molded sole.

5. That improvement in methods of preparing outsoles for incorporation into shoes which consists in molding into the desired form a shank-shape preserving element of moldable metal that is too stifl" to mold satisfactorily simultaneously with tempered sole leather; assembling the molded shape preserving element with a tempered sole blank; then molding the sole blank to the shape previously imparted to the said element; and then maintaining the sole and the shape retaining element in exact assembled relation until incorporated in a shoe.

6. That improvement in methods of preparing outsoles for incorporation into shoes which consists in molding a shank-shape preserving element, including the longitudi nal and transverse curvatures, into the shape desired in the shank portion of a shoe and forming thereon integral attaching prongs; assembling said element and a sole blank with the prongs directed toward the sole blank, molding the sole blank to the shape previously given to the said element and rendering permanent the identity of shape of the said two elements by attaching them together by the prongs.

- 7. That improvement in methods of preparing outsoles for incorporation into shoes which consists in molding a shank-shape preserving element, including the longitudinal and transverse curvatures, into the shape desired in the shank portion of a shoe and forming thereon integral attaching prongs;- assembling said element and a sole blank with the prongs directed toward the sole blank and located at the corners of said shape-preserving element, bending the sole longitudinally and transversely into the shape previously imparted to said element and attaching the bent sole to the shape-preserving element by the prongs to hold the sole in its bent shape.

In testimony whereof I have signed my name to this specification.

KARL ENGEL. 

